Variation analyses of growth and wood properties of Larix olgensis clones in China

Abstract

The growth traits (tree height, diameter at breast height, and stem straightness degree) and wood properties [wood density (WD), fiber length, fiber width, ash content (AC), lignin content, cellulose content, hemicellulose content (HEC), and holocellulose content] of 208 26-year-old Larix olgensis clones were analyzed. Except for WD and AC, there were significant differences (p < 0.01) for all traits among clones. The phenotypic coefficient of variation and repeatability of all traits were 9.34–35.33% and 0.218–0.930, respectively. Tree height and diameter at breast height showed significant positive correlation; however, the correlation coefficients among growth characteristics and wood properties were mostly not significant. Ten clones (L70, L56, L82, L90, L59, L91, L61, L92, L86, and L64) were selected as excellent clones under a selection rate of 5%, using tree height, diameter at breast height, and stem straightness degree as evaluation indexes, providing genetic gains of 28.69, 17.96, and 0.67%, respectively. Ten clones (L88, L305, L59, L66, L253, L304, L277, L298, L248, and L293) were selected as excellent clones using wood properties as an evaluation index, with a selection rate of 5%, providing genetic gains in WD, fiber length, fiber width, cellulose content, and HEC of 4.14, 3.64, 9.28, 6.77, and 9.61%, respectively. This study provides a theoretical basis for selecting excellent L. olgensis clones.